仿蝎机器人步态分析及结构设计

随着国内管道运输系统的广泛应用,智能化管道检测技术的开发显得日益重要。在研究了国内外仿生机器人和并联机器人的基础上,对蝎子的行走过程进行了观察和记录,得到了大量的步态分析数据,并应用仿生学、运动学设计理论根据生物原形提出了仿蝎机器人的整体结构方案及各转动关节的转动数据,通过设计计算得到了其详细的机械结构尺寸,根据蝎子的尺寸比例设计了仿蝎机器人三维模型,为进一步进行仿蝎机器人样机在管道检测领域的应用奠定了坚实的基础。     

变频器的巧用

本文主要阐述我公司在安装净化空调过程中发现电机的额定电流过大,超出已安装的电气线路的承受范围.我们利用变频器的变频原理,巧妙地解决了这一问题.     

不同头部结构的半穿甲战斗部侵彻效能分析

为提高半穿甲弹侵彻有限厚钢靶板效能,研究半穿甲战斗部在不同头部结构下的动态响应。建立了5种不同头部结构模型,对比头部结构对穿甲效果的影响。运用ANSYS/LSDYNA模拟半穿甲战斗部侵彻过程并加以分析,得到侵彻过程中的速度变化与攻角变化等。研究表明,穿透靶板后尖顶型具有更高的侵彻效能;将有限加大的防跳环附在弹头中部,可以增大半穿甲战斗部跳飞角度。     

微车座椅面套的巧妙设计

重点阐述微车后排座椅护面总成的巧妙设计,在护面总成上设计了固定插销口袋,随车工具袋,解决了后排座椅固定插销带来的易脏与异响问题,同时也解决了车内凌乱和随车工具易丢失的问题。     

制造复杂模板时钢锯片的巧用

中、小型企业在制作一些复杂的模板时,其内腔材料的去除常采用钻连排细小(或较大)孔,然后再用錾子錾去多余材料的方法。此方法在制造过程中,稍不注意,经常将小钻头折断在工件之中,从而给内腔材料的去除带来了困难。文中提出了一种简便的加工方法,在加工复杂模板零件时,可较好地解决去除模板内腔材料的问题。     

转换方法的巧用

为适应汉语语言的表达习惯，使译文清晰、通顺、达意，通常要酌情转变原文中的词性、句子成分，甚而转换句型。     

三爪自定心卡盘的巧用

通过实例介绍了车床三爪自定心卡盘在复杂零件加工装夹过程中的巧妙应用,相对于在四爪卡盘上装夹及在花盘、铁铁上的装夹方法,效果显著提高.     

An Analysis of the Multiscale Structure of Surfaces with Various Finishes

Even with the various surface finishing techniques, all surfaces are rough with different structures and geometric characteristics over multiple scales. In this work, a profilometer is utilized to measure the profiles of different rough surfaces, and the profiles are characterized using a variety of statistical, spectral, and fractal methodologies. Three different methods are implemented in calculating the fractal dimension, D, and these three methods are then compared. The relationship between the fractal dimension and the fractal scaling constant, G, is investigated as well. The measured rough profiles are also compared with Weierstrass-Mandelbrot (W-M) function–generated rough profiles using the characterization results of the measured profiles. After comparing a series of statistical and fractal parameters, which are calculated based on the surface profile data of the original and regenerated profiles, it can be found that the W-M function does not always appear to be very suitable for representing measured rough profiles. Another important conclusion is that many measured profiles are not always consistent with the quality of self-affinity that many of the popular fractal models assume. Therefore, a discrepancy exists between idealized fractal equations and real profiles. However, these findings are limited to the measurement resolution and specific surfaces considered in this work.     

非光滑表面对汽车尾涡结构的控制分析研究

车身气动阻力直接影响汽车的动力性和燃油经济性,尾涡结构对于车辆空气阻力的形成有很大的影响,非光滑结构在车身的合理布置能有效地减小汽车的空气阻力。为了研究车身非光滑结构对汽车尾涡结构的影响与控制,将凹坑型非光滑单元分别布置在MIRA阶梯背模型尾部、顶部、行李舱盖等表面,运用计算流体力学(Computational fluid dynamics,CFD)数值仿真与风洞试验相结合的方法,对比分析车身表面光滑模型与车身表面非光滑模型尾部流场的压力、湍流耗散率、速度矢量等参数的影响,探讨非光滑结构的扰动效应及其对尾涡形成的控制作用,得出非光滑结构能延迟气流分离,控制后风窗上猫眼涡与尾部剪切涡流,也能抑制汽车尾部主涡的生成。为有效控制车辆尾迹中旋涡结构,抑制涡激振动,改善汽车气动特性提供重要依据。     

液压传动在汽车精细控制中的巧妙应用

汽车在工作时的动作是瞬息万变的,现代汽车要求控制系统在极短的时间内跟踪这样的变化速度,对有关部件进行精细控制,保证汽车总是处于最佳工作状态。现代液压传动系统向灵敏、准确、快捷、智能方向发展,与光、电结合组成的智能控制系统能够满足汽车精细控制的要求,气门正时智能可变控制就是这种巧妙应用的例子之一。     

汽车钢板强度影响安全性能

提到汽车安全,以往人们大多关注安全气囊、ESP等主被动安全配置,现在,业界又开始关心汽车钢板强度的问题。有些人认为,钢板的强度对车辆安全更重要,实际情况是这样吗?事件一:2011年11月21日,中华首款SUV——中华V5全国上市。它在媒体中公开宣布整车全面采用新一代吸能式高强度钢化车     

汽车制动系统中排气的独创性解决方案

为了解决原制动系统管路中的排空气方法存在的制动行程大、排气效率低等问题,我们通过试验验证,提出了采用负压式排气的方法,这一独创性的解决方案,取得了预期的效果。     

运用PLC实现钢板弹簧自动剪切生产线

介绍了钢板弹簧剪切生产线的工艺流程,提出了利用PLC为控制核心,用光电编码器和高速计数器组成测长装置,构成能实现高精度定长剪切功能的自动生产线。该系统可靠性高,操作方便,效果良好。     

The Contact of Elastic Regular Wavy Surfaces Revisited

We revisit the classic problem of an elastic solid with a two-dimensional wavy surface squeezed against an elastic flat half-space from infinitesimal to full contact. Through extensive numerical calculations and analytic derivations, we discover previously overlooked transition regimes. These are seen in particular in the evolution with applied load of the contact area and perimeter, the mean pressure and the probability density of contact pressure. These transitions are correlated with the contact area shape, which is affected by long range elastic interactions. Our analysis has implications for general random rough surfaces, as similar local transitions occur continuously at detached areas or coalescing contact zones. We show that the probability density of null contact pressures is nonzero at full contact. This might suggest revisiting the conditions necessary for applying Persson’s model at partial contacts and guide the comparisons with numerical simulations. We also address the evaluation of the contact perimeter for discrete geometries and the applicability of Westergaard’s solution for three-dimensional geometries.     

卷板机辊子断裂的探析

通过对辊子的受力和弯扭应力、磨损机理、磨损磨合的分析,结合对辊子的设计、工艺及卷扳机的使用过程,指出了辊子断裂的潜在原因,并提出了相应的解决措施.     

Nanoscale Reciprocating Sliding Contacts of Textured Surfaces:Influence of Structure Parameters and Indentation Depth

Textured surfaces are widely used in engineering components as they can improve tribological properties of sliding contacts, while the detailed behaviors of nanoscale reciprocating sliding contacts of textured surfaces are still lack of study. By using multiscale method, two dimensional nanoscale reciprocating sliding contacts of textured surfaces are investigated. The influence of indentation depth, texture shape, texture spacing, and tip radius on the average friction forces and the running-in stages is studied. The results show that the lowest indentation depth can make all the four textured surfaces reach steady state. Surfaces with right-angled trapezoid textures on the right side are better for reducing the running-in stage, and surfaces with right-angled trapezoid textures on the left side are better to reduce wear. Compared with other textured surfaces, the total average friction forces can be reduced by 82.94%–91.49% for the case of the contact between the tip with radius R = 60r_0 and the isosceles trapezoid textured surface. Besides,the total average friction forces increase with the tip radii due to that bigger tip will induce higher contact areas. This research proposes a detailed study on nanoscale reciprocating sliding contacts of textured surfaces, to contribute to design textured surfaces, reduce friction and wear.     

陶瓷/KFRP双板复合构件的孔加工

工程陶瓷和Kevlar纤维增强复合材料(简称KFRP)都是难加工材料,陶瓷/KFRP双板复合构件的孔加工比较困难。在分析双板复合构件组成材料的加工技术现状的基础上,采用专门研制的烧结金刚石钻头对其进行加工试验研究,探讨了其工艺特点,分析了影响加工效率的主要因素。     

组态软件在钢板弹簧自动剪切生产线中的应用

介绍了钢板弹簧剪切生产线的工艺流程，利用PLC和力控软件开发了一个自动生产线的监控系统。该系统可靠性高，操作方便，效果良好。     

The Energy of Electrons Emitted from Wearing Solid Surfaces

The energy of electrons emitted during the scratching of solids by a diamond stylus was measured using a retarding-potential energy analyzer in a vacuum of 10^-4–10^-5 Pa. The solids tested were insulators, a semiconductor and a conductor. The insulators were normal sintered alumina (Al₂O₃), polymethylmethacrylate (PMMA) and glass, the semiconductor was n-type silicon (Si) and the metal was aluminum (Al). The energy of emitted electrons was distributed from low values to beyond 900 eV for the insulators and from low values to about 100 eV for the semiconductor, while that of metals could not be measured because the electron emission intensity was too low to be detected. The energy of the electrons emitted from metals was inferred from previous reports to be less than about 2 eV. These results lead to the conclusion that the electric field caused by tribocharging accelerates the electrons to give the energy of electrons increasing in the order of insulator > semiconductor > conductor. This is because electric resistivity is chiefly responsible for generating the surface potential—a function of both electric resistivity and dielectric constant.